Physical Chemistry PYQ — Page 58

A bacterial infection in an internal wound grows as ${N}^{'}(t)={N}_{0}exp⁡(t)$ , where the time $t$ is in hours. A dose of antibiotic, taken orally, needs 1 hour to reach the wound. Once it reaches there, the bacterial population goes down as $\frac{dN}{dt}=-5{N}^{2}$ . What will be the plot of $\frac{{N}_{0}}{N}$ vs $t$ after $1$ hour?

An ideal gas is allowed to expand from $1 L$ to $10 L$ against a constant external pressure of $1$ bar. The work done in $kJ$ is:

The vapour pressures of pure liquids $A$ and $B$are $400$ and $600\mathrm{mm}\mathrm{Hg}$ respectively at $298 K.$On mixing the two liquids, the sum of their volumes is equal to the volume of the final mixture. The mole fraction of liquid $B$ is $0.5$ in the mixture. The vapour pressure of the final solution, the mole fractions of components $A$ and $B$ in the vapour phase, respectively are

The process with negative entropy change is:

The osmotic pressure of a dilute solution of an ionic compound $XY$ in water is four times that of a solution $0.01 M BaC{l}_{2}$ in water. Assuming complete dissociation of the given ionic compounds in water, the concentration of $XY$ ( $in mol {L}^{-1}$ ) in solution is

Given that, ${E}_{{O}_{2}/{H}_{2}O}^{o}=+1.23V;$ ${E}_{{S}_{2}{O}_{8}^{2-}/{\mathrm{SO}}_{4}^{2-}}^{o}=2.05V$ ${E}_{{\mathrm{Br}}_{2}/{\mathrm{Br}}^{-}}^{o}=+1.09V;$ ${E}_{{\mathrm{Au}}^{3+}/\mathrm{Au}}^{o}=1.4V$ The strongest oxidizing agent is

Decomposition of $X$ exhibits a rate constant of $0.05 \mu g/\mathrm{year}$. How many years are required for the decomposition of $5 \mu g$ of $X$ into $2.5 \mu g$?

If solubility product of $Z{r}_{3}{(P{O}_{4})}_{4}$ is denoted by ${K}_{sp}$ and its molar solubility is denoted by $S$ , then which of the following relation between $S$ and ${K}_{sp}$ is correct?

A $10 \mathrm{mg}$ effervescent tablet containing sodium bicarbonate and oxalic acid releases $0.25 \mathrm{~mL}$ of $\mathrm{CO}_{2}$ at $\mathrm{T}=298.15 \mathrm{~K}$ and $\mathrm{P}=1$ bar. If molar volume of $\mathrm{CO}_{2}$ is $25.0 \mathrm{~L}$ under such condition, what is the percentage of sodium bicarbonate in each tablet? [Molar mass of $\left.\mathrm{NaHCO}_{3}=84 \mathrm{~g} \mathrm{~mol}^{-1}\right]$

Which of the following lines correctly show the temperature dependence of equilibrium constant $K,$ for an exothermic reaction? 

Two 5 molal solutions are prepared by dissolving a non-electrolyte, non-volatile solute separately in the solvents $\mathrm{X}$ and $\mathrm{Y}$. The molecular weights of the solvents are $\mathrm{M}_{\mathrm{X}}$ and $\mathrm{M}_{\mathrm{Y}}$, respectively where $\mathrm{M}_X=\frac{3}{4} \mathrm{M}_{\mathrm{Y}}$. The relative lowering of vapour pressure of the solution in $\mathrm{X}$ is " $\mathrm{m}$ " times that of the solution in Y. Given that the number of moles of solute is very small in comparison to that of solvent, the value of "m" is:

A sample of ${\mathrm{NaClO}}_{3}$ is converted by heat to $\mathrm{NaCl}$ with a loss of $0.16g$ of oxygen. The residue is dissolved in water and precipitated as $\mathrm{AgCl}$. The mass of $\mathrm{AgCl}$ (in $g$) obtained will be: (Given: Molar mass of $\mathrm{AgCl}=143.5 g {\mathrm{mol}}^{-1}$)

$\Delta_{\mathrm{f}} \mathrm{G}^{\circ}$ at $500 \mathrm{~K}$ for substance ' $\mathrm{S}$ ' in liquid state and gaseous state are $+100.7 \mathrm{kcal} \mathrm{mol}^{-1}$ and $+103$ $\mathrm{kcal} \mathrm{mol}^{-1}$, respectively. Vapour pressure of liquid ' $\mathrm{S}$ ' at $500 \mathrm{~K}$ is approximately equal to: $$ \left(\mathrm{R}=2 \mathrm{cal} \mathrm{K}^{-1} \mathrm{~mol}^{-1}\right) \text {. } $$

For$1\mathrm{molal}$aqueous solution of the following compounds, which one will show the highest freezing point?

An ideal gas undergoes a cyclic process as shown in the figure  $\Delta {U}_{\mathrm{BC}}=-5{\mathrm{KJmol}}^{-1},{q}_{\mathrm{AB}}=2{\mathrm{KJmol}}^{-1}$ ${W}_{\mathrm{AB}}=-5{\mathrm{KJmol}}^{-1},{W}_{\mathrm{CA}}=3{\mathrm{KJmol}}^{-1}$ Heat absorbed by the system during process $\mathrm{CA}$is

Given (i) $2 \mathrm{Fe}_2 \mathrm{O}_3(\mathrm{~s}) \rightarrow 4 \mathrm{Fe}(\mathrm{s})+3 \mathrm{O}_2(\mathrm{~g})$; $$ \Delta_{\mathrm{r}} \mathrm{G}^{\circ}=+1487.0 \mathrm{~kJ} \mathrm{~mol}^{-1} $$ (ii) $2 \mathrm{CO}(\mathrm{g})+\mathrm{O}_2(\mathrm{~g}) \rightarrow 2 \mathrm{CO}_2(\mathrm{~g})$; $$ \Delta_{\mathrm{r}} \mathrm{G}^{\circ}=-514.4 \mathrm{~kJ} \mathrm{~mol}^{-1} $$ Free energy change, $\Delta_{\mathrm{r}} \mathrm{G}^{\circ}$ for the reaction $2 \mathrm{Fe}_2 \mathrm{O}_3(\mathrm{~s})+6 \mathrm{CO}(\mathrm{g}) \rightarrow 4 \mathrm{Fe}(\mathrm{s})+6 \mathrm{CO}_2(\mathrm{~g})$ will be:

The minimum volume of water required to dissolve 0.1 g lead (II) chloride to get a saturated solution ( ${K}_{sp}$ of ${PbCl}_{2}=3.2\times {10}^{-8}$ ;atomic mass of $Pb=207 u$ ) is:

Ejection of the photoelectron from metal in the photoelectric effect experiment can be stopped by applying $0.5V$, when the radiation of $250\mathrm{nm}$ is used. The work function of the metal is

An unknown chlorohydrocarbon has 3.55 % of chlorine. If each molecule of the hydrocarbon has one chlorine atom only; chlorine atoms present in 1 g of chlorohydrocarbon are :(Atomic wt. of $\mathrm{Cl}=35.5 u;$ Avogadro constant $=6.023\times {10}^{23} {\mathrm{mol}}^{–1}$)

Which of the following are Lewis acids?

Which of the following salts is the most basic in aqueous solution?

In which of the following reactions, an increase in the volume of the container will favour the formation of products?

Ejection of the photoelectron from metal in the photoelectric effect experiment can be stopped by applying $0.5 \mathrm{~V}$ when the radiation of $250 \mathrm{~nm}$ is used. The work function of the metal is :

The de-Broglie's wavelength of electron present in first Bohr orbit of ' $\mathrm{H}$ ' atom is: